Off-cells: a place of work for Casentinesi Forests

\u201cOff-cells. Un luogo del lavoro per le Foreste Casentinesi\u201d \ue8 il progetto presentato alla Biennale di Venezia 2018 da Diverserighestudio, uno dei cinque gruppi di progettazione selezionati per il Padiglione Italia dal Curatore Mario Cucinella. \u201cArcipelago Italia\u201d guarda ai territori distanti, fuori dalle citt\ue0 e dalle aree urbane maggiori: l\u2019area di boschi secolari al confine tra Toscana ed Emilia Romagna ha, ancor pi\uf9 di altre, stimolato a riflettere sulle potenzialit\ue0 che le risorse materiali del luogo offrono all\u2019architettura e sulla rete di relazioni che esse possono alimentare, diventando occasioni di rilancio di sistemi insediativi indeboliti da decenni di marginalizzazione, ma ancora straordinariamente ricchi di potenzialit\ue0."Off-cells. A place of work for Casentinesi Forests\u201c is the project presented at Biennale di Architettura 2018 in Venice by Diverserighestudio, one of the five design groups selected for Italian Pavilion by the Curator Mario Cucinella. \u201cArcipelago Italia\u201d looks to distant territories, outside the cities and major urban areas: this area of secular woods on the border between Tuscany and Emilia Romagna has, even more than others, stimulated to reflect on both the potential that the material resources of the place offer to architecture and the network of relationships that they can form, becoming opportunities for relaunching settlement systems weakened by decades of marginalization, but still extraordinarily rich in potential

Musculoskeletal modelling of the human cervical spine for the investigation of injury mechanisms during axial impacts

This is the final version. Available from Public Library of Science via the DOI in this record.All relevant data are available at Figshare [https://figshare.com/projects/SILVESTROS_PLOS_ONE_SUPPORTING_DOCUMENTS/58280] and musculoskeletal models and relevant project information is available on the OpenSim SimTK repository [https://simtk.org/projects/csibath].Head collisions in sport can result in catastrophic injuries to the cervical spine. Musculoskeletal modelling can help analyse the relationship between motion, external forces and internal loads that lead to injury. However, impact specific musculoskeletal models are lacking as current viscoelastic values used to describe cervical spine joint dynamics have been obtained from unrepresentative quasi-static or static experiments. The aim of this study was to develop and validate a cervical spine musculoskeletal model for use in axial impacts. Cervical spine specimens (C2-C6) were tested under measured sub-catastrophic loads and the resulting 3D motion of the vertebrae was measured. Specimen specific musculoskeletal models were then created and used to estimate the axial and shear viscoelastic (stiffness and damping) properties of the joints through an optimisation algorithm that minimised tracking errors between measured and simulated kinematics. A five-fold cross validation and a Monte Carlo sensitivity analysis were conducted to assess the performance of the newly estimated parameters. The impact-specific parameters were integrated in a population specific musculoskeletal model and used to assess cervical spine loads measured from Rugby union impacts compared to available models. Results of the optimisation showed a larger increase of axial joint stiffness compared to axial damping and shear viscoelastic parameters for all models. The sensitivity analysis revealed that lower values of axial stiffness and shear damping reduced the models performance considerably compared to other degrees of freedom. The impact-specific parameters integrated in the population specific model estimated more appropriate joint displacements for axial head impacts compared to available models and are therefore more suited for injury mechanism analysis.Rugby Football Union (RFU) Injured Players Foundatio

Femoral component rotation of a modern tka implant does not affect pfj biomechanics

Patellofemoral joint (PFJ) complications, such as anterior knee pain, are a common complaint among knee arthroplasty patients and femoral rotational mal-alignment is thought to be a contributing factor. However, no studies have assessed the effect of femoral internal and external rotation on PFJ biomechanics using simulated physiological loading cycles. The present study aimed to assess the effect of surgical femoral rotational alignment errors on the forces, moment arms and contact areas within the PFJ. Testing was carried out under physiological loading, with a quasi-static kinematic knee joint simulator, using Scorpio NRG prostheses implanted on synthetic bones. Three scenarios were simulated, to replicate the worst case in terms of surgical error; neutral placement was compared to 5° internal and 5° external femoral rotation.External rotation caused a significant reduction in the patella moment arm. However, femoral rotational mal-alignments of ± 5° had no clinically relevant effect on the quadriceps force, patella compressive force, or PFJ contact areas. For all scenarios, the PFJ was subjected to over 65% lateral loading and consistent edge loading of the patella button. This study demonstrates that, in terms of PFJ biomechanics, the Scorpio NRG implant used was tolerant of surgically relevant levels of femoral rotational mal-alignment. <br/

The Effect of Femoral Rotation During Total Knee Arthroplasty on Patellofemoral Contact Characteristics

Patellofemoral joint (PFJ) complications are a common cause of dissatisfaction leading to revision total knee arthroplasty (TKA) due to wear and/or pain. It is thought that increased contact pressures and forces within the PFJ contribute to increased incidences of pain and wear of the patella button. Previous work suggests that this may be associated with femoral component rotation and hence this should be controlled tightly during surgery; but the available data are limited. This study aimed to assess the influence of femoral component rotation on the quadriceps forces, and the contact areas and compressive forces within the PFJ using an in vitro, non-cadaveric, TKA model. Static and dynamic tests were carried out using a six degrees of freedom vertical knee simulator designed to replicate motion of an average UK woman. The movement at the knee is driven by actuation of the quadriceps model. The hamstrings are modelled physiologically by two cables each with a constant tension of 50N. Scorpio PS size 7 (Stryker, NJ) components were implanted in composite bones by an orthopaedic surgeon and primary ligaments were modelled using synthetic cords. The required quadriceps force to achieve extension during a squat and the associated patella compressive forces were assessed using single axis load cells. The PFJ centre of pressure (COP) was measured using a pressure array (Novel, Munich) and the contact areas assessed using pressure film (FujiFilm). Three femoral positions were assessed (neutral, 5° internal and 5° external rotation) each with a 5 mm medialised patella dome and a centrally placed asymmetric patella button. Six repeats were carried out.Irrespective of patella button type, femoral external rotation caused an increase of up to 10% in the required quadriceps force and compressive PFJ forces, likely due to the alteration of the Q angle caused by the component rotation. Internal rotation caused corresponding reductions. These trends are only significant in mid-flexion and are masked by increased loading. The patella button geometry also appeared to influence the degree to which femoral rotation affected the PFJ. Fewer differences were demonstrated with the medialised dome, which was associated with increasing lateral COP measurements post-TKA with external rotation. In contrast, the asymmetric dome demonstrated medial COP shifts with external rotation.In conclusion, PFJ forces and pressures are influenced by a complex combination of prosthesis geometry and component positioning. As little as 5° of femoral rotation may have an implant specific, detrimental effect on the PFJ